Codeforces Round 993 (Div. 4)

9 problems from Codeforces Round 993 (Div. 4) (contest 2044), difficulty 800-2100. 7/9 solutions verified against sample I/O.

9 items

Codeforces Round 993 (Div. 4)

Div. 4 | 9 problems | 7/9 verified | Difficulty 800-2100 | 18m 25s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Easy Problem	800	brute-force, math	61,178	1m 17s	✓
B	Normal Problem	800	implementation, strings	51,953	1m 30s	✓
C	Hard Problem	800	greedy, math	45,251	1m 32s	✓
D	Harder Problem	1100	constructive-algorithms, greedy, math	24,095	3m 26s
E	Insane Problem	1300	binary-search, greedy, implementation	18,064	1m 30s	✓
F	Easy Demon Problem	1900	binary-search, brute-force, data-structures	6,038	2m 4s	✓
G1	Medium Demon Problem (easy version)	1700	dfs-and-similar, graph-matchings, graphs	7,312	2m 24s	✓
G2	Medium Demon Problem (hard version)	1900	dfs-and-similar, dp, dsu	3,819	2m 50s
H	Hard Demon Problem	2100	constructive-algorithms, data-structures, dp	2,582	1m 52s	✓

Practice › Codeforces Solutions › Codeforces Round 993 (Div. 4) ›

CF 2044H - Hard Demon Problem

We are given an $n times n$ matrix of positive integers and multiple queries, each specifying a rectangular submatrix.

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CF 2044G2 - Medium Demon Problem (hard version)

The error in your Python solution is a simple syntax mistake: the map(int, input().split()) call for reading b is missing a closing parenthesis. This prevents the code from running at all. Once that is fixed, the solution logic itself can remain the same.

Practice › Codeforces Solutions › Codeforces Round 993 (Div. 4) ›

CF 2044G1 - Medium Demon Problem (easy version)

Each spider chooses exactly one recipient. We can view this as a directed graph where every vertex has out-degree exactly one. Initially every spider owns one plushie. During a year, every spider that currently has a plushie sends one plushie along its outgoing edge.

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CF 2044D - Harder Problem

We are asked to construct an array b from a given array a such that for every prefix of b up to index i, the element a[i] is one of the modes of that prefix.

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CF 2044F - Easy Demon Problem

We are given two arrays, a and b. From them we build an implicit matrix $$M{i,j}=ai bj.$$ The beauty of the matrix is the sum of all its entries.

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CF 2044E - Insane Problem

We are asked to count the number of pairs of integers $(x, y)$ that satisfy two interval constraints and a geometric relationship. Specifically, $x$ must lie in the interval $[l1, r1]$, $y$ must lie in $[l2, r2]$, and $y / x$ must be an integer power of $k$.

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CF 2044C - Hard Problem

We are asked to assign monkeys to seats in a classroom with exactly two rows of m seats each. The monkeys come in three categories: a monkeys that will only sit in the first row, b monkeys that will only sit in the second row, and c monkeys that have no preference.

Practice › Codeforces Solutions › Codeforces Round 993 (Div. 4) ›

CF 2044B - Normal Problem

We are given a string consisting only of the letters p, q, and w. Ship observes this string from outside a glass window, giving us string a. When Ship moves inside the store and looks through the same window, he sees string b. Our task is to determine what b looks like given a.

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CF 2044A - Easy Problem

We are asked to count ordered pairs of positive integers $(a, b)$ such that $a + b = n$, for multiple test cases. Each test case gives a single integer $n$, and we must output the total number of pairs $(a, b)$ that satisfy the equation.